Yes, it’s Part 1 as there are so many tools available and choices to make.
And it’s all about using your mobile device to make the content.
Luckily, I’ve already gone through a bunch of options and hopefully can lead you to right choices for you.
First of all is the basic capture.
And deciding if you are looking to create interviews or scenario type of videos, or be the presenter, ala selfie.
To start: For interviews
Bring out your phone, choice the orientation, and hit video or cinema on the camera app, and go!
It does work great, and if you are a steady hand, you’ll get usable content. No need to buy anything!
BTW, Apple just released a free video app called Final Cut Camera, which gives you a deeper dive into video options. Just downloaded, and seeing how it compares to others.
Depending on your scenario, you may want to add the Joby Beamo magsafe light, or the ShiftCam SnapLight to fill in the shadows a bit.

Easy right?
I use this approach a lot especially on the street, if I’m also capturing stills. Fast, not intimidating, decent sound (more on that later!)
The lights will also do you right when doing the selfie type vids. Shoot, post to social, and there you go.

But you knew all of this.

Let’s get into the tools that up the level.
The simplest and effective gear is the ShiftCam SnapGrip creator kit system.

Using MagSafe, it attaches easily, and fast to your camera, and incorporates a BT shutter release, and a battery so you are charging your camera while it’s mounted. Knowing that the phone ischarging while you shoot is a big comfort factor

It’s easy to orient your camera in a vertical or horizontal direction.
To up the set-up you can stack add their magsafe light, which has an additional mirrored surface to allow you or your subject to see what is being videoed.
Not sure that you want your subject to watch themselves, but it does get their eyeline into the proper camera lens. Maybe most useful when doing presenter or selfie, the now current vlog format, while making sure you are in the frame.
The ShiftCam system does incorporate a magsafe extendable arm that connects to a mini tripod to give your arm some distance.
I do wish there was a standard ¼-20 thread to give options for mounting.
Another add-on recommended is the magsafe SnapShoe.

It kind of stacks with the others and lets you add a different light to your rig, or maybe an external mic!
And alternate to this is the Ulanzi magsafe grip. This is also BT, and has a built-in cold shoe, and a ¼-20 thread on the bottom. No built in battery.

Which one is best for you? The Snap is def a more robust build, and the built in battery assured me I wouldn’t go dark when recording. Plus, it has a case to keep it from getting trashed in your camera bag.

Then we get into the camera cages that give you many more possibilities to add on accessories to the rig.
My main is the Beastgrip. With a solid build, and ability to adjust to many diff phone sizes, this is my first choice. A spring loaded holder,not mag safe, and a bunch for ¼-20 threads to add extras.

With plenty of ¼ -20 threads to add cold shoes to mount lights, mics, SSD drives, plus a great handle, when covering trade shows, this rig has the raw capability I need.
Another option is the SmallRig Universal phone Video Rig Kit, which also has the ability to add things, And the form is more of a 2 handed balance with cold shoes in the handles.

It does have a much larger footprint than the Beastgrip, once all things included are added on. I do see it on sale now and again at BH, and have purchased for about $120, same price as the Beastgrip, although it comes with a ton of extras (light, mic,tripod), and a case. The Small Rig full kit does have an extra holder for an external battery to keep you from running out of power. Or an SSD drive
Admittedly I have pillaged the Small Rig accessories to add onto the Beastgrip and Snap.

Neither of the Beastgrip or SmallRig are mag safe as of this writing.
In other words, you need to put your phone in and secure via a spring-loaded grip or screw tighten holder.

Ok, we have now gone from simple and light, to complex and heavier.
Covered some small footprints with the grip options.

Next up in Part 2 is audio!